递质对牛脑不溶部分与钠和钾亲和力的影响。

The effects of transmitters on the affinity of the insoluble fraction of ox brain for Na+ and K+.

作者信息

Ahmed N, Hillman H

机构信息

Unity Laboratory of Applied Neurobiology, University of Surrey, Guildford, England.

出版信息

Neurochem Res. 1989 Feb;14(2):179-84. doi: 10.1007/BF00969636.

DOI:10.1007/BF00969636

PMID:2566940

Abstract

The insoluble fraction of ox-brain, which had previously been shown to have a non-linear affinity for Na+ and K+, was prepared. Acetylcholine (1 x 10(-8) mol/l and 1 x 10(-7) mol/l) reduced the affinity of the fraction for Na+ and K+ to zero, while at 1 x 10(-6) mol/l, the affinity for the cations was almost as high as in the absence of the transmitter; the affinities for Na+ and K+ were particularly high, when the supernatant concentrations of these ions exceeded 80-100 mM. Addition of eserine (3 x 10(-5) mol/l) considerably modified the response of the fraction to acetylcholine (1 x 10(-5) mol/l). Atropine (1 x 10(-8) mol/l) in the absence or presence of acetylcholine (1 x 10(-5), or 1 x 10(-4) mol/l) reduced the affinity of the fraction for Na+ and K+ to zero. Epinephrine (3 x 10(-10) mol/l) lowered the affinity for Na+ and K+, while ergotamine itself (1 x 10(-5) mol/l) reduced it to zero. The addition of both epinephrine and ergotamine at the latter concentrations restored the affinity of the fractions for Na+ and K+ to what it had been in the absence of the transmitter or antagonist, previously reported. Norepinephrine (3 x 10(-10) mol/l), or ouabain (1 x 10(-7) mol/l) reduced the affinity of the fraction for Na+ and K+ to zero. Thus, the transmitters and antagonists altered the affinity of the insoluble fraction for Na+ and K+ non-linearity, dependent upon their concentrations, the concentrations of the cations, and the interaction of transmitter and antagonist.

摘要

制备了牛脑的不溶性部分，此前已证明其对Na⁺和K⁺具有非线性亲和力。乙酰胆碱（1×10⁻⁸mol/L和1×10⁻⁷mol/L）将该部分对Na⁺和K⁺的亲和力降低至零，而在1×10⁻⁶mol/L时，对阳离子的亲和力几乎与不存在递质时一样高；当这些离子的上清液浓度超过80 - 100 mM时，对Na⁺和K⁺的亲和力特别高。加入毒扁豆碱（3×10⁻⁵mol/L）显著改变了该部分对乙酰胆碱（1×10⁻⁵mol/L）的反应。在不存在或存在乙酰胆碱（1×10⁻⁵或1×10⁻⁴mol/L）的情况下，阿托品（1×10⁻⁸mol/L）将该部分对Na⁺和K⁺的亲和力降低至零。肾上腺素（3×10⁻¹⁰mol/L）降低了对Na⁺和K⁺的亲和力，而麦角胺本身（1×10⁻⁵mol/L）将其降低至零。以后者浓度同时加入肾上腺素和麦角胺可使该部分对Na⁺和K⁺的亲和力恢复到先前报道的在不存在递质或拮抗剂时的水平。去甲肾上腺素（3×10⁻¹⁰mol/L）或哇巴因（1×10⁻⁷mol/L）将该部分对Na⁺和K⁺的亲和力降低至零。因此，递质和拮抗剂改变了不溶性部分对Na⁺和K⁺的非线性亲和力，这取决于它们的浓度、阳离子的浓度以及递质和拮抗剂的相互作用。